Case Studies

Greater than the sum of its parts – the FAULHABER GROUP's vision is built on diversity of technologies, people, companies  and capabilities, on solution oriented, customer centric approaches to complex challenges and a burning passion to offer advanced products at the boundary of the possible without leaving practicality behind.

Case Study: Micromotors speed up PCB assembly
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Story courtesy of FAULHABER Drive Systems
www.faulhaber.com

Micromotors speed up PCB assembly

Ask any mass-market manufacturer and they will tell you what they require from their assembly lines: performance and accuracy. Find out how FAULHABER teamed up with Siemens on its SIPLACE X Series to provide electronics manufacturers with a new and better means of PCB assembly; one that lowers cost and increases productivity.

Today, mass-market electronics are manufactured almost exclusively on high-performance assembly machines. Given the nature of these fast-moving products, time is literally money. Therefore, two aspects are of particular importance for the production equipment deployed within this area: maximum quantities and minimum changeover time. For the manufacturer of such machines this means ensuring best possible output, combined with simple processing in a continuous operation. This requirement can only be fulfilled if the complex operational sequence remains accurate and reproducible at all times. As Siemens found, micromotors are an essential component in fulfilling this requirement and turned to its partner FAULHABER to help.

The complexities of PCB manufacture

Supply modules with standard belt widths in 8, 12, 16 to 88 mm

Siemens developed its cutting-edge SIPLACE X Series with the aim of providing electronics manufacturers worldwide with an even more effective solution for printed circuit board (PCB) assembly. As is the case with all mechanically sophisticated machines, the issue of drive technology was also of pivotal importance, and it’s here that FAULHABER’s expertise was required.

An assembly machine consists of independent components, all of which have to operate “in sync”. A placement head attached to a mobile portal collects the components from a conveyor and then transports them to the assembly position. The quicker and less frequently this “journey” has to be made, the quicker a product can be manufactured.

Another significant element is the supply of components. Currently, components are delivered on belts and by rollers. The belt rollers enter into a conveyor, and the belt travels in such a way that a component is always ready for collection by the placement head. As part of this process it is essential to maintain both the exact receiving position and the receiving speed of the head.

The 20-segment Collect & Place (C&P) unit, as the heart of this state-of-the-art machine, therefore had to be able to hold as many components as possible at any one-time, despite being built to be ultra-light, so as to reduce its mass inertia.

Enabling unprecedented control through micromotors

20-segment Collect & Place unit

The design engineers solved this problem with the new 20-segment C&P unit. The head is capable of extracting and holding the components in place via negative pressure from pipettes. A camera records the components connected to the pipette, compares the position with the target position and issues a command for the micromotor on the pipette to turn to the correct position. To be able to support all 20 pipettes, each with their own motor, FAULHABER created a highly specialized design tailored precisely to the space available for a compact, light-build solution.

Instead of using two separate controllers for the motors and the other components of the head, the team opted for synergy. The control electronics for the motors are integrated into the control board of the other components, thus taking up substantially less space. The size and mass are scaled down and assembly performance increased.

Greater efficiency; better performance

Until recently, the standard for component feed was a conveyor with a width of 30 mm or more, which could accommodate one, two or three belts (standard belt widths: 8, 12, 16 up to 88 mm wide). When changing a component, all belts had to be exchanged with the conveyor; even if only one component was different. In order to increase efficiency, the aim was to incorporate three independent conveyors in the designated space of approx. 30 mm provided by the Triple Feeder.

Up until then comparatively “large” micromotors, at 15 mm in diameter, were used for the drives. However, the requirement for the new motors in the X-Feeder was a maximum diameter of approx. 10 mm. Thanks to special high-energy magnets, these new motors are capable of achieving performance levels like those associated with conventional 20…25 mm motors. When one considers that performance normally increases or decreases in motors along with the square of the diameter, the achievement by the design engineers is all the more impressive.

Working in partnership, FAULHABER and Siemens have brought greater efficiency and accuracy to PCB assembly, helping manufacturers worldwide lower costs and increase productivity.

Case Study: Micro-Precise Surgery Assistant
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Story courtesy of MPS
www.mpsag.com

Micro-Precise Surgery Assistant

Accurate to a Millimetre

The surgical profession is all about accuracy, particularly when it comes to spinal surgery. Read how Mazor Surgical Technologies teamed up with FAULHABER subsidiary MPS to create a robotic surgical assistant; which helps serve as a guiding tool for difficult spinal surgeries and thereby helps to improve patient outcomes.

Mazor Surgical Technologies, was established in 2001 as a spin-off of the mechanical department of the Israel Institute of Technology. Mazor specializes in the development of medical robots, with precision mechanics manufacturing outsourced to FAULHABER subsidiary, MPS. Working together the two companies are focused on providing medical professionals with the tools they need to improve patient outcomes. One such tool is the SpineAssist system which Mazor Surgical Technologies and MPS have created to bring greater precision to spinal surgery.

A matter of millimetres

Accuracy and precision in implant placement is critically important in spinal surgery since most procedures are performed close to the nerve roots and spinal cord, where every millimetre counts. Spinal fusion is a surgical intervention that is performed for various reasons including to straighten the spine and prevent further deformation due to scoliosis or other disorders; to support a weakened or injured spine, or to reduce or prevent pain from pinched or injured nerves.

Although spinal fusion is associated with a high rate of success, implant misplacement was disconcertingly high. Misplacement is associated with a heightened risk of neural and vascular complications, as well as injury to the spinal cord membrane.

Collaborating with MPS, Mazor Surgical Technologies built the SpineAssist; a bone-mounted system which accurately guides surgeons for maximum precision when placing implants destined to stabilize spinal (vertebrae) fusions in both open and minimally invasive surgery.

In addition to a miniature hexapod robot, the system consists of preoperative planning software with automatic fluoroscopic and CT image processing and a set of rigid bone fixation clamps and platforms. The system enables an arm on the hexapod robot to automatically position itself at the exact location identified in the preoperative plan and serve as a guiding tool when the surgeon drills or performs some other intervention on the bone.

The overall system accuracy and repeatability is less than 100 microns and 10 microns respectively. The motion control accuracy is of 10 microns. When you take into account human influence and the CT- and fluoroscopic-image distortion, the system accuracy in placing an implant with respect to the preoperative plan is of less than 1.5 mm. Enabling this sort of precision required precision machinery.

Engineering for control

Six of FAULHABER’s DC brushless smoovy® gear motors with custom drive electronics drive the linear actuators based on a high precision, miniature lead screw design. Accurate and absolute displacement measurement is meanwhile assured by seven LVDT sensors, one for each actuator and the seventh tracking the performance of the others.

The miniature size of the hexapod involved several design challenges, where one of the most important one probably was finding a miniature drive solution. The smoovy® DC servomotor, measuring only 5 mm in diameter, proved an excellent trade-off between miniature size and required torque and speed for the application. The overall thigh tolerances for small dimensions and the precision of the M2.5 custom thread lead screw, as well as precision actuator ball and socket joints are all examples of engineering specifications that make the hexapod a true manufacturing triumph.

Improving patient outcomes

The SpineAssist software for image processing and pre-surgical planning

With the SpineAssist, a spinal fusion intervention can now be performed with only a couple of small incisions; compared to open surgery where a large incision potentially causes more muscle damage. This innovation both reduces the risk of infection and bleeding while making the whole experience much less traumatic for the patient. Patients also benefit from a decreased stay in hospital and a shorter recovery time.

The miniature size of the robot with no need for “line of sight” and its high accuracy simplifies the surgical procedure and minimizes the risk for screw misplacement. Since the robot is rigidly attached to the patient there is no need for a tracking coordinate system. The procedure using the SpineAssist only requires a few fluoroscopic images, adding reduced radiation exposure for the surgeon and the patient as an important benefit to the system.

By helping surgeons be more accurate than the human eye allows, SpineAssist helps them do their jobs better, improving patient outcomes.

Case Study: How to catch a comet?
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Story courtesy of FAULHABER Drive Systems
www.faulhaber.com

How to catch a comet?

Harpoon unit for secure anchoring on the surface of the comet

Landing a probe on a comet is no easy feat, yet in 2014 that’s exactly what the European Space Agency did. Find out how drives from FAULHABER helped ensure the Agency’s lander, Philae, could negotiate low gravity and the temperature extremes of space to land safely, and complete a world first for space science.

On November 12, 2014 the world looked on as for the first time a man-made craft touched down on the surface of a comet. Philae, a European Space Agency lander, completed the first ever successful soft-landing on a comet: 67P/Churyumov-Gerasimenko. The lander has subsequently provided scientists with unprecedented information on the composition of the comet and done much to further our understanding of the universe. However, the success of this project was never guaranteed: first there were a number of engineering challenges which needed to be overcome. Through its innovative, light-weight drives, FAULHABER helped European Space Agency technicians do just that.

Anchoring on a comet

One of the key challenges which faced the European Space Agency at the start of the project lay in building drives that would enable Philae, which weighs 100 kg, to securely position itself on the comet. Part of this challenge was ensuring that the compact ballistic drives the lander would use to propel itself would function after the ten years it would spend in space en route to the comet.

The Max Planck Institute for Extra-terrestrial Physics and the German Aerospace Centre had developed a special anchor system for the probe, which allowed it to get a firm footing on the surface of the low-gravity comet. Immediately after landing, two harpoons would be shot by a propellant charge into the surface of the comet. After the shot, this cable would be wound up on a drum by the micromotor until taut, which firmly anchored the probe on the surface. Once the cable has been tightened, a DC motor would apply tension to a coil spring positioned on the reel shaft. This would help absorb any possible sinking of the harpoon or the landing legs of the sensor. Additional drives were also in use; such as on the three-legged landing gear of the lander and the microdrives that were needed for taking samples.

The demands that outer space place on these drives are high, and every kilo of mass that is shot into space costs energy, i.e. fuel – hence money too. Therefore, small, light solutions were needed. At the same time, however, they must also be able to withstand the enormous forces experienced during take-off, as well as the constant very-low temperatures and the many years of vacuum conditions prevailing in outer space. Finally, because the cost factor also plays a major role in all considerations when selecting components for space projects, the developers wanted to do without costly custom developments if at all possible.

Drive systems fit for space

Brushless DC-Servomotor
Ø 16 mm, length 28 mm Torque 3.3 mNm

They found what they were looking for in the comprehensive drive systems product range from FAULHABER.

The lander's legs were connected with the top section by way of a cardan joint in which three motors were integrated. Thanks to their compact dimensions, the drive solutions could be easily integrated and their low power requirements were also ideally suited to the application.

The lubrication of all drives used in the lander were specially-adapted to the conditions in space. Greases or oils are ineffective under these circumstances; they either solidify in the cold of outer space or vaporise in the vacuum. It was therefore decided to use molybdenum disulphide (MoS2) for the space mission, which has a graphite-like layer structure. This lubrication functions in a vacuum and in the frigid temperatures of outer space, but also at temperatures of up to several hundred degrees Celsius.

Finally, the gearhead housing had to be made suitable for deployment in outer space. Deep temperatures of less than -100 °C and can lead to thermal expansion problems with precision parts due to blockage. For this reason, the standard nickel-plated brass housing of the drive was replaced by a steel housing, which is matched to the thermal expansion rates of the steel gears.

Mission complete

The lander's legs are connected with the top part by way of a cardan joint in which three motors are integrated: two for both of the tilting axes and one for adjusting the brake force of the multi-plate clutches.

The standard drive solutions offered by FAULHABER fulfilled all the mechanical requirements of the mission. The European Space Agency could therefore rise to the challenges of operating in space, while making comparably few modifications and accruing negligible additional costs. The results spoke for themselves: a highly successful landing, a world first, and a wealth of new scientific information.

Case Study: Smooth Operation
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Story courtesy of MPS
www.mpsag.com

Smooth Operation

The Swiss watch industry remains a byword for timepiece excellence worldwide. The excellence of the manufacturers is matched by world-class suppliers that help them to create the highest-quality watches in the world. Find out how MPS, a subsidiary of FAULHABER, helps Swiss watch manufacturers create complex yet accurate works of horological art. 

The Swiss watch industry remains a byword for timepiece excellence worldwide. Switzerland's edge over its rivals is based on long tradition, a unique accumulation of know-how, and a broad infrastructure of top-class supplier companies. These companies manufacture the high-quality parts from which the coveted timepieces are made and which are often miniature marvels in themselves. For example, the almost microscopic ball bearings from MPS, a subsidiary of FAULHABER.

The art of time

Almost 30 million wristwatches are manufactured in Switzerland every year – that's only one fortieth of total worldwide production. With this modest share, however, Swiss watchmakers generate 54 percent of the global turnover. The reason for this can be summed up in two words: precision engineering. These watches do not simply tell the time; they compensate for the earth’s gravitational pull (though so-called ‘tourbillon’) and house everything from stopwatches to perpetual calendars in casings of mere centimetres; all without impairing the accuracy of the watch.

Hundreds of moving parts must interact perfectly and reliably so that such watches can be produced and function continuously and precisely. One of the biggest enemies of accuracy and durability is friction. To minimize friction, miniature ball bearings are used in high-quality mechanical watches. The majority of these are produced by MPS.

Perfectly precise ball bearings

The balls are made from sections of drawn stainless-steel wire or from ceramic zirconium oxide granulate. In both cases, processing can take up to several weeks. In a multistage process, the tiny raw components are first formed into balls on grinding discs with precisely shaped grooves, ground finer and finer on numerous discs, and finally polished. When they are ready, the maximum deviation in diameter, roundness and surface roughness is in the nanometre range.

All balls – 35 to 40 million leave the factory every year – undergo several final checks, including visual inspection under the microscope. Here skilled employees roll a batch of balls, of which the smallest have a diameter of just 0.14 millimetres, backwards and forwards in a kind of pill box. Their trained eyes pick up any remaining deviations and anomalies – after the balls have already been examined and measured by machine.

On the other side of the highlands, directly on the French border, in Bonfol, MPS Watch builds probably the tiniest ball bearings available on the market. The smallest have an outer diameter of just 1.28 millimetres. "In 2004 we were the first manufacturer to use ceramic balls in clockwork bearings. Since last year we have offered Myrox, the first fully ceramic ball bearing", says Frédéric Chautems, factory manager in Bonfol. "Ceramic is considerably harder than metal and is practically indestructible. It does not need lubrication and still achieves extremely low friction coefficients.”

MPS also manufactures the components of the bearing housing – ring, core, cone and cage – itself because here too the utmost precision and reliable quality is crucial. Assembling the balls and housing into a functioning bearing is an art in itself and is performed by hand by highly specialized employees.

Apart from the ball bearings, other watchmaking elements are also produced in Bonfol, e.g. turned parts, rotors or a mounting kit for the tourbillon that makes the installation and removal of this ingenious function easier. Thanks to an extremely innovative development department, MPS has registered many patents and, technologically, has a considerable edge over its competitors – and not only in the case of ceramic bearings.

A time honoured tradition

The art of watchmaking dates back 500 years, but it is an industry that continually looks to enhance performance and innovate. MPS’ precisely engineered ball bearings play a highly significant role in helping Swiss watchmakers do just that.

And it’s not only watchmakers that are benefitting from these parts. MPS builds a wide range of different bearings and systems to meet the needs of any industry where mechanical accuracy is critical: from medical technology to aerospace.